wave_mechanics dopplers_effect Question 51
Question: A car sounding a horn of frequency 1000 Hz passes an observer. The ratio of frequencies of the horn noted by the observer before and after passing of the car is 11 : 9. If the speed of sound is v, the speed of the car is
[MP PET 2002]
Options:
A) $ \frac{1}{10}v $
B) $ \frac{1}{2}v $
C) $ \frac{1}{5}v $
D) v
Show Answer
Answer:
Correct Answer: A
Solution:
$ n _{Before}=\frac{v}{v-v _{c}}n $ and $ n _{After}=\frac{v}{v+v _{c}}.n $
$ \frac{n _{Before}}{n _{After}}=\frac{11}{9}=( \frac{v+v _{c}}{v-v _{c}} ) $
Therefore $ v _{c}\Rightarrow \frac{v}{10} $
BETA
